不同脂肪源对细鳞鲑生长、脂质代谢及抗氧化性能的影响

EFFECTS OF DIFFERENT LIPID SOURCES ON THE GROWTH, LIPID METABOLISM AND ANTIOXIDANT ABILITY OF BRACHYMYSTAX LENOK

配制4种含有鱼油(FO)、菜籽油(CO)、棕榈油(Pa O)和大豆油(SO)的饲料投喂初始体重为(22.19±1.10)g的细鳞鲑幼鱼52d,探讨不同脂肪源对细鳞鲑(Brachymystax lenok)幼鱼生长、脂质代谢及抗氧化性能的影响。结果显示,增重率、特定生长率和饲料效率均以鱼油和大豆油组最高,棕榈油组次之,菜籽油组最低,其中大豆油组与鱼油组无显著差异(P>0.05)。不同脂肪源对细鳞鲑幼鱼肌肉粗成分无显著影响(P>0.05)。摄食大豆油的细鳞鲑可以明显提升肌肉中的22:6n-3含量,表明细鳞鲑具有将18:3n-3转化为22:6n-3的能力,n-3系列脂肪酸是细鳞鲑起主要作用的必需脂肪酸。与鱼油相比,植物油脂导致了细鳞鲑血清中甘油三酯含量的显著升高以及胆固醇含量的显著降低,肝脏中ACC1和FAS的m RNA表达量明显下调,以及Δ6 Fad的m RNA表达量的明显上调(P<0.05)。投喂不同脂肪源饲料的细鳞鲑肝脏ROS、MDA、GPx含量以及TBARS值发生明显变化(P<0.05)。研究结果表明鱼油和大豆油可作为细鳞鲑幼鱼饲料的脂肪源,而棕榈油和菜籽油不适宜作为细鳞鲑幼鱼的单一脂肪源。

A 52-day growth trial was conducted to evaluate the effects of different dietary lipids on the growth performance, lipid metabolism, and antioxidant ability of Brachymystax lenok. Fish with average initial weight of（22.19±1.10） g were fed with four experimental diets that contained fish oil（FO）, colza oil（CO）, palm oil（Pa O）, and soybean oil（SO）,respectively. The lowest weight gain, specific growth rate, and the feed conversion ratio were observed with CO treatment, while the highest values of these parameters occurred at the experiments of FO and SO, with no significant differences between these two conditions（P〉0.05）. Crude protein and lipid in the muscle of Brachymystax lenok were not affected by lipid sources（P〉0.05）. However, the DHA level of Brachymystax lenok fed with SO increased, which indicated that Brachymystax lenok had the ability to desaturate and elongate from 18：3 n-3 to 22：6 n-3. Compared to which fed with FO, an increase of TG and decrease of TC were observed in the serum of Brachymystax lenok fed with plant oils. In addition, the m RNA expression of Δ6 Fad in the liver of those fed with plant oils also increased, but the m RNA expression of ACC1 and FAS decreased. The values of ROS, MDA, GPx and TBARS in liver were significantly affected by different lipid sources（P〈0.05）. The results suggest that FO and SO could be used in the diet for juvenile Brachymystax lenok, but CO and Pa O are unsuitable as single lipid sources for juvenile Brachymystax lenok.